1) Field of the Invention
The present invention is directed to an extensible torpedo.
2) Description of Prior Art
The ability to extend or telescope following deployment is known for projectiles including undersea vehicles and torpedoes. One known mechanism for extending an undersea vehicle or torpedo following launch is a slide mechanism. In a slide mechanism, a shaft member at the aft section of the projectile is slidably mounted on a boom extending from the body of the projectile. The shaft slides along the boom in a contained manner. The projectile is initially assembled with the shaft in the forward most position. The shaft is retained in the forward position until the projectile exits the launch tube. After exiting the launch tube, the shaft slides to a rear-flight position and is locked in this position during flight. The mechanism for extending the projectile to its flight length configuration utilizes the high-pressure gas from the burning propellant of the projectile. As an alternative, a separate solid propellant or compressed gas cylinder is provided in the projectile boom causing the shaft to slide to the flight position.
Some extensible projectiles create a cavity, or increase an existing cavity volume, upon extension. One example is an unmanned underwater vehicle having a first tail cone portion with an internal cavity and a second tail cone portion positionable in and axially extensible from the cavity. Prior to separation of the vehicle from a ram plate, the tail cone second portion is held against the first portion by that ram plate. After separation of the vehicle from the launch tube, a spring urges the tail cone second portion rearwardly to an extended position, lengthening the vehicle and increasing the volume of the internal cavity.
Other projectiles include a compartment within their bodies. A flexible bladder is contained within the compartment and may be extended or retracted using a variety of materials, including air or water. For example, inlets in the body are connected through a conduit to a pump. The pump draws ambient water from around the underwater vehicle through the inlet and conduit and into the flexible bladder, thereby extending it.
For explosive projectiles, reactive materials are often housed within the projectile; however, the mass of these materials often adversely affects projectile maneuverability. In explosive projectiles that use water as a reactive material, this mass is particularly burdensome. In addition, reactions that use water are slowed by an excess amount of water that cools the reaction. Slowing of the reaction decreases the effectiveness of the explosive projectile.